Hi guys,
I got a response from Greg. 
Greg referred me to this video How to Work with Stereo Virtual Instruments in Mono | Q&A with Greg Ondo - YouTube which I have watched before… and followed. But the results were inconsistent as I have already mentioned. 
But this time I unchecked the Cubase Only box. Essentially, if you want to get mono tracks for your Superior Drummer 3 drums follow the video and just replace the reference to GA with SD3 and you’re golden. 
I hope this helps someone out